High melting temperature polymers, such as polyimide polymers having a glass transition temperature that can range from about 180° C. to about 450° C. have found utility in a variety of applications because of their currently extreme physical properties in addition to their heat resistant properties. For example, polyetherimides, available from General Electric Company under the ULTEM® trademark have high glass transition temperatures, are ductile, flame resistant and generate low amounts of smoke while still having good chemical resistivity. These polymers have found wide use in shaped articles, sheet materials, and coatings for use in challenging physical environments such as aerospace applications.
Despite their high processing temperatures, high performance polymers, such as polyetherimides can be made into fibers, however, they require higher processing temperatures not generally used for processing other polymeric fibers. These processing conditions often lead to unexpected and difficult processing issues in the commercial manufacture of articles.
In a conventional system for making polymer fiber, polymer resin is extruded in an extruder and passed through a spinneret containing a plurality of hole openings to form a fiber bundle which is cooled, and drawn to a spool or coil. High performance polymers, such as polyetherimides, require higher processing temperatures not generally used for processing other polymeric fibers. These processing conditions often lead to unexpected and difficult processing issues in the commercial manufacture of articles and fiber. In addition, the output production rate of fibers generated from materials having high melt temperature or high glass transition temperatures are typically low, which limits on the cost-effectiveness for these materials in a variety of product applications. There is therefore a continuing need in the art to develop processes for high heat materials being used to make fibers.